Sagittal Balance Parameters after Anterior Cervical Discectomy with Spondylodesis and Arthroplasty Using Endocarbon Endoprosthesis: Results of Randomized Study.

The aim of the study was to examine the effect of cervical segment mobility on spinal sagittal balance parameters after cervical total disc arthroplasty (CTDA) and anterior cervical discectomy and fusion (ACDF) using the first domestic intervertebral disc endoprosthesis. Materials and Methods: The randomized prospective study included 98 patients (48 with CTDA, 50 with ACDF). Implants used: intervertebral disc endoprosthesis or intervertebral fusion cage (Endocarbon; NPP "MedInzh", Russia).Total cervical mobility and range of motion in the target and adjacent vertebral motion segments were studied by functional radiography before surgery, at an early postoperative period (within 3 days), and 3, 6, and 12 months after the intervention.Values of cervical lordosis (CL, °), cervical sagittal vertical alignment (cSVA, mm), and first thoracic vertebra slope (T1 slope, °) were determined by using spinal radiography. Surgimap V2.2 software (Nemaris, USA) was used for measurements. Results: When comparing changes of overall cervical mobility at different time intervals, statistically significant differences were obtained in ACDF group (p=0.001). When comparing this parameter between ACDF and CTDA, a statistically significant difference was found only at the early postoperative period (p=0.004).In CTDA group, the range of motion increased at the operated segment (p=0.001) and decreased at the caudal segment (p=0.002). In ACDF group, no motion was observed at the operated segment (p=0.001) and the range of motion increased at adjacent segments (p=0.001). A statistically significant difference between ACDF and CTDA was obtained only at the operated (p=0.001) and caudal segments (p≤0.002).Correlation analysis showed no dependence between range of motion influence and regional/global balance values (p>0.5).The intergroup comparison of cervical lordosis (CL) values revealed a statistically significant difference after 6 (p=0.001) and 12 (p=0.001) months. The best results were obtained at ACDF group towards lordosis increase (p=0.001). The relationship between cervical lordosis and arthroplasty of segments C5-C6, C6-C7 (p=0.003; ρ=0.41) was determined using correlation analysis. The correlation between CL and ACDF (p=0.001; ρ=0.72) was also established.cSVA comparison between groups showed no difference at preoperative period (p=0.215), 6 (p=0.20) and 12 (p=0.425) months after surgery. cSVAs at both groups were equally close to normal values.T1 slope changes before and 12 months after surgery were statistically significant at ACDF (p=0.008) and CTDA (p=0.001) groups. T1 slope values comparison between ACDF and CTDA shows statistically significant difference after 12 months (p=0.003). T1 slopes were equally close to normal values 1 year after surgical treatment. Conclusion: Over a 12-month observation period, the segmental range of motion was found to have no effect on changes of regional and global balance of the cervical spine. No influence was confirmed of range of motion on adjacent level syndrome development - the syndrome was diagnosed in none of the cases.This study demonstrated the effectiveness of arthroplasty using an Endocarbon endoprosthesis in improving cSVA and T1 slope values, but no significant improvement of CL values after treatment compared to ACDF group.

Application of 2D Gait Analysis for the Assessment of Gait Disturbance in Patients with Spastic Tetraparesis.

The aim of the study was to explore the use of 2D gait analysis for assessing gait abnormalities in patients with spastic tetraparesis associated with spinal cord injury and other lesions of the cervical spinal cord. Materials and Methods: The study included 12 patients with tetraparesis of various etiologies. Gait assessment was performed by video analysis using reflective markers (1.5 cm) and a special walking platform. The spatial coordinates of the markers were determined by capturing the reflected light with infrared LEDs located around the lenses of video cameras. Results: Using 2D gait analysis, numerical indicators of gait disturbance in spastic tetraparesis were obtained. We found a prolongation of the stand phase with a shortening of the swing phase (from 81.9 [76.1; 89.2] to 85.3 [74.4; 90.2]%; p=0.97) and the period of the double step (from 0.50 [0.45; 0.96] to 0.40 [0.34; 0.66]; p=0.4) in comparison with the target (normal) values (60% - for the stand phase; 1.41 - for the double-step period). The movements in the hip, knee, and ankle joints are described using numerical values.We then compared the data obtained from the left and right sides of the patient's body: there were no statistically significant differences between the two sets of data. We also compared the gait characteristics before and after treatment (in 4 patients). Statistically significant differences in values were obtained for the stand and swing phases (p=0.035), the range of motion in the hip joint (p=0.01), and gait velocity (p=0.046). Kendall's analysis revealed no significant correlation between the data obtained by video gait analysis and the gait changes by the Modified Ashworth Scale (р>0.05). Conclusion: 2D gait analysis is a promising method for quantifying gait disturbance in patients with spastic tetraparesis. It allows one to identify characteristic gait patterns, in particular, an increase in the stand phase with a shortening of the swing phase and the double step period, as well as a decrease in the range of motion in the hip joints with an increase in the knee and ankle ones.